Ge self-assembled quantum dots （SAQDs） are grown with a self-assembled UHV/CVD epitaxy system. Then, the as-grown Ge quantum dots are annealed by ArF excimer laser. In the ultra-shot laser pulse duration, -20ns, bul...Ge self-assembled quantum dots （SAQDs） are grown with a self-assembled UHV/CVD epitaxy system. Then, the as-grown Ge quantum dots are annealed by ArF excimer laser. In the ultra-shot laser pulse duration, -20ns, bulk diffusion is forbidden,and only surface diffusion occurs, resulting in a laser induced quantum dot （LIQD）. The diameter of the LIQD is 20-25nm which is much smaller than the as-grown dot and the LIQD has a higher density of about 6 ×10^10cm^-2. The surface morphology evolution is investigated by AFM.展开更多
In this study,a KrF excimer laser was used to modify the biodegradable Mg-1Ca alloy and the time-evolution degradation behavior of the alloy before and after laser treatment was investigated in simulated body fluid(SB...In this study,a KrF excimer laser was used to modify the biodegradable Mg-1Ca alloy and the time-evolution degradation behavior of the alloy before and after laser treatment was investigated in simulated body fluid(SBF)solution using immersion tests and electrochemical impedance spectroscopy(EIS).A 5μm melted layer with a homogeneous microstructure and an MgO film on the surface were achieved by laser radiation.Corrosion observations(hydrogen evolution,morphology and corrosion products)and EIS results revealed an improvement of corrosion resistance after laser treatment for 48 h.It was found a two-layer structure developed after 2 h immersion on both the untreated and laser-treated alloys,but the sequence of forming the two layers was opposite and greatly influenced by the laser-treated layer.The time-evolution corrosion processes on the untreated and laser-treated alloys were discussed,providing a better understanding of corrosion behavior of biodegradable Mg alloys modified by excimer laser.展开更多
AIM:To investigate the size of functional optical zone(FOZ)after small incision lenticule extraction(SMILE)versus femtosecond laser assisted excimer laser keratomileusis(FS-LASIK)for myopia correction and potential as...AIM:To investigate the size of functional optical zone(FOZ)after small incision lenticule extraction(SMILE)versus femtosecond laser assisted excimer laser keratomileusis(FS-LASIK)for myopia correction and potential associated factors for FOZ.METHODS:A total of 133 patients who received corneal refractive surgery in our hospital between November 2018 and July 2021 were retrospectively enrolled.There were 63 patients(123 eyes)in SMILE group and 70patients(139 eyes)in FS-LASIK group.The size of FOZ was measured using Pentacam 3-dementional anterior segment analyzer before and 3mo after surgery,so as to analyze postoperative achieved functional optical zone(AFOZ)and its contributing parameters.RESULTS:When planned functional optical zone(PFOZ)was 6.5 mm for both groups,AFOZ was 1.45±0.27 and 1.67±0.25 mm smaller than preoperative FOZ in SMILE group and FS-LASIK group 3mo after surgery.AFOZ in SMILE group was significantly larger than that in FS-LASIK group(P<0.001).Variation of FOZ was negatively correlated with preoperative spherical equivalent(SE)and positively correlated with variation of mean keratometry value(△Km),variation of spherical aberration(△SA),and variation of Q-value(△Q,all P<0.001)in both groups.Multiple variable linear regression equations were△FOZ=1.354-0.1×pre-SE+0.336×△Q+1.462×△SA in SMILE group and△FOZ=1.512+0.137×△Q+0.468×△SA in FS-LASIK group.CONCLUSION:AFOZ is significantly smaller than preoperative FOZ in both SMILE and FS-LASIK groups.With the same PFOZ,larger AFOZ is achieved in SMILE group than in FS-LASIK group.展开更多
BACKGROUND Percutaneous coronary intervention can be challenging for ostial coronary artery lesions due to calcium burden and elastic fiber content.Excimer laser coronary atherectomy(ELCA)is a less common treatment fo...BACKGROUND Percutaneous coronary intervention can be challenging for ostial coronary artery lesions due to calcium burden and elastic fiber content.Excimer laser coronary atherectomy(ELCA)is a less common treatment for severe calcified coronary ostium lesions.CASE SUMMARY An 81-year-old male presented to the Cardiology Department of Qingdao Municipal Hospital with a 1-year history of chest pain.Coronary angiography showed severe calcific stenosis(approximately 90%)in the right coronary artery ostium.The right coronary artery ostium was unable to be advanced using a 2.5 mm×12.0 mm balloon(NC Sprinter,Medtronic,United States)or dilated using a 2.0 mm×12.0 mm balloon(Sprinter,Medtronic,United States).The patient underwent successful ELCA and balloon dilation of the calcified coronary ostium lesion.CONCLUSION ELCA appears to be a safe and effective treatment for the management of severe calcified coronary ostium lesions.展开更多
Polycrystalline silicon （poly-Si） thin film has been prepared by means of nickel-disilicide （NiSi2） assisted excimer laser crystallization （ELC）. The process to prepare a sample includes two steps. One step cons...Polycrystalline silicon （poly-Si） thin film has been prepared by means of nickel-disilicide （NiSi2） assisted excimer laser crystallization （ELC）. The process to prepare a sample includes two steps. One step consists of the formation of NiSi2 precipitates by heat-treating the dehydrogenated amorphous silicon （a-Si） coated with a thin layer of Ni. And the other step consists of the formation of poly-Si grains by means of ELC. According to the test results of scanning electron microscopy （SEM）, another grain growth model named two-interface grain growth has been proposed to contrast with the conventional Ni-metal-induced lateral crystallization （Ni-MILC） model and the ELC model. That is, an additional grain growth interface other than that in conventional ELC is formed, which consists of NiSi2 precipitates and a-Si. The processes for grain growth according to various excimer laser energy densities delivered to the a-Si film have been discussed. It is discovered that grains with needle shape and most of a uniform orientation are formed which grow up with NiSi2 precipitates as seeds. The reason for the formation of such grains which are different from that of Ni-MILC without migration of Ni atoms is not clear. Our model and analysis point out a method to prepare grains with needle shape and mostly of a uniform orientation. If such grains are utilized to make thin-film transistor, its characteristics may be improved.展开更多
The diffusion and the activation of phosphorus in phosphorus and fluorine co-implanted Ge after being annealed by excimer laser are investigated.The results prove that the fluorine element plays an important role in s...The diffusion and the activation of phosphorus in phosphorus and fluorine co-implanted Ge after being annealed by excimer laser are investigated.The results prove that the fluorine element plays an important role in suppressing phosphorus diffusion and enhancing phosphorus activation.Moreover,the rapid thermal annealing process is utilized to evaluate and verify the role of fluorine element.During the initial annealing of co-implanted Ge,it is easier to form high bonding energy FnVm clusters which can stabilize the excess vacancies,resulting in the reduced vacancy-assisted diffusion of phosphorus.The maximum activation concentration of about 4.4 ×10^(20) cm^(-3) with a reduced diffusion length and dopant loss is achieved in co-implanted Ge that is annealed at a tailored laser fluence of 175 mJ/cm^(2).The combination of excimer laser annealing and co-implantation technique provides a reference and guideline for high level n-type doping in Ge and is beneficial to its applications in the scaled Ge MOSFET technology and other devices.展开更多
We report on the impact of direct ultraviolet germicidal irradiation（UVGI）on reflective optics,used in the excimer laser system Allegretto Eye-Q.The aim of our work was to confirm our hypothesis based on long-rate o...We report on the impact of direct ultraviolet germicidal irradiation（UVGI）on reflective optics,used in the excimer laser system Allegretto Eye-Q.The aim of our work was to confirm our hypothesis based on long-rate observations of obtained anomalies in post-operative results that are attributed to degradation of reflective optics upon ultraviolet radiation.The presence of direct UVGI coupled with humidity in the operating environment caused merging anomalies and unwanted post-operative correction values.Ultraviolet-A radiation caused a similar effect on the reflective cover of the mirrors.展开更多
Surface of Al 2O 3 ceramic was processed by an excimer laser and the characteristics of topography were examined based on the application of the microelectromechanical system(MEMS). It is indicated that the statisti...Surface of Al 2O 3 ceramic was processed by an excimer laser and the characteristics of topography were examined based on the application of the microelectromechanical system(MEMS). It is indicated that the statistic parameters of surface topography processed by the excimer laser have an obvious regularity. The arithmetic-mean value R a and the root-mean square value R q change with the changing of processing parameters in the same step and trend, and there is a quantitative relation between them.A simplified model is proposed for the excimer laser processing surface profile, whose results of the analysis and calculation agree basically with the experimental data. Furthermore,the surfaces processed by excimer laser are greatly flat. Skewness root-mean-square value Z· q changed little with the change of the technological parameters. The above characteristics depend on the processing principle of excimer laser, quite different from the cutting processing.展开更多
Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3, Al2O3-SiC nanocomposite and Si3N4). Al2O3 and AI2O3-SiC nanocomposite samples ex...Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3, Al2O3-SiC nanocomposite and Si3N4). Al2O3 and AI2O3-SiC nanocomposite samples exhibit a smooth rapid melt layer on the surface, and the formation of the metastabfe γ-Al2Oa was observed. A silicon-rich layer on the surface was formed after laser irradiation of Si3N4. The toughness K1c of the materials was measured by the indentation fracture method. After laser irradiation, the toughness of Al2O3, Al2O3-SiC nanocomposite and Si3N4 was improved to various degrees: Al2O3-SiC nanocomposite, 60% (max.); AI203, 40% (max.); Si3N4, 12% (max.).展开更多
Thin metallic layers (~ 2 μm) of Ni were deposited on polycrystalline Al2O3. ZrO2 and (Ce-TZP)+Al2O3 ceramic substrates. and further irradiated with pulsed excimer (Xeno chloride) laser pulses. The laser energy densi...Thin metallic layers (~ 2 μm) of Ni were deposited on polycrystalline Al2O3. ZrO2 and (Ce-TZP)+Al2O3 ceramic substrates. and further irradiated with pulsed excimer (Xeno chloride) laser pulses. The laser energy density was varied from 0.21 to 0.81 J / cm2 to optimize bending strength. For ZrO2 ceramic, it was found that the strength increases from 530 to 753 MPa at 0.51 J / cm2 irradiation. For Al2O3 and (Ce-TZP)+ Al2O3 the fracture strength also increases in varying degree. The causes of strength increment were discussed.展开更多
Ablation experiments of A950 Liquid Crystal Polymer (LCP), as a kind of typical matrix of fibre reinforced polymer composites, are carried out in this paper. Data on the ablation of A950 LCP by excimer laser at 24...Ablation experiments of A950 Liquid Crystal Polymer (LCP), as a kind of typical matrix of fibre reinforced polymer composites, are carried out in this paper. Data on the ablation of A950 LCP by excimer laser at 248 nm are presented. The experimental results show that the ablation depth is a linear function of the number of pulse at constant laser fluence, The ablation rate varies with the logorithm of the fluence in a linear manner at different fluences. A satisfactory linear relationship is found between ablation energy and incident fluence. Perhaps due to the plume absorption and thermal effect, the ablation rate varies complicatedly with pulse repetition frequency.展开更多
The 193 nm deep-ultraviolet(DUV)laser plays a critical role in advanced semiconductor chip manufacturing[1,2],micro-nano material characterization[3,4]and biomedical analysis[5,6],due to its high spatial resolution an...The 193 nm deep-ultraviolet(DUV)laser plays a critical role in advanced semiconductor chip manufacturing[1,2],micro-nano material characterization[3,4]and biomedical analysis[5,6],due to its high spatial resolution and short wavelength.Efficient and compact 193 nm DUV laser source thus becomes a hot research area.Currently,193 nm Ar F excimer gas laser is widely employed in DUV lithography systems and serves as the enabling technology for 7 and 5 nm semiconductor fabrication.展开更多
Background Children with anisometropic amblyopia are often noncompliant with traditional treatment including spectacules and contact lenses. This study was to evaluate the long-term efficacy of excimer laser in situ k...Background Children with anisometropic amblyopia are often noncompliant with traditional treatment including spectacules and contact lenses. This study was to evaluate the long-term efficacy of excimer laser in situ keratomileusis （LASIK） for children with high anisometropic amblyopia. Methods A retrospective analysis of 24 children with high unilateral anisometropic amblyopia, who underwent LASIK during the period between August 2000 and September 2005 in our hospital, was conducted. The mean age of these children was （7.4±1.9） years （range 5-14 years） and the mean follow-up period was （33.3±14.2） months （range 18.5-74.2 months）. After LASIK, visual acuity, refraction and far or near stereoacuity were analyzed. Near stereoacuity was measured by the random-dot butterfly stereogram and the pre-school random-dot stereogram, while far stereoacuity was measured by the synoptophore with Yan＇s random-dot stereogram. Results Mean preoperative uncorrected visual acuity was 0.06±0.05, while mean postoperative uncorrected visual acuity was elevated to 0.43±0.33. Mean preoperative best-corrected visual acuity was 0.26±0.22, while mean postoperative best-corrected visual acuity was elevated to 0.67±0.40. For patients with myopic anisometropia, preoperative mean spherical equivalent refraction was （-8.01±2.70） D while postoperative value significantly reduced to （-1.32±2.47） D. For patients with hyperopic anisometropia, preoperative mean spherical equivalent refraction was （ 7.35±1.55） D while postoperative value significantly reduced to （3.30±0.86） D. These results demonstrated that there was statistical difference in these parameters between preoperative and postoperative tests. At the last follow-up, 20 patients had near stereoacuity, and the mean near stereoacuities measured by the random-dot butterfly stereogram and the preschool random-dot stereogram were （149.00±152.93）＂ and （201.05±235.94）＂, respectively. In contrast, 11 patients had far stereoacuity, and the mean far stereoacuity measured by the synoptophore was （210.91±217.51）. Three cases of patients developed mild corneal complications. Conclusion LASIK for the correction of high anisometropia in children with monocular amblyopia may be safe and effective, and this can help effectively conduct postoperative amblyopia training and improve the cure rate.展开更多
A method to fabricate fiber Bragg grating （FBG） in an optical microfiber （OM） from a conventional photosensitive fiber is proposed in this letter. The cladding of a conventional photosensitive fiber is etched to 1...A method to fabricate fiber Bragg grating （FBG） in an optical microfiber （OM） from a conventional photosensitive fiber is proposed in this letter. The cladding of a conventional photosensitive fiber is etched to 17 pro. The etched fiber is drawn to an OM 6μm in diameter. The photosensitivity of the fabricated OM is effectively reserved. A FBG in the OM （MFBG） is successfully fabricated using a KrF excimer laser at a fluence of 400 mJ/cm2 through a phase mask with a pitch of 1 089.3 nm. The reflectivity of the FBG is approximately 10%, and the 3-dB spectrum bandwidth is 0.13 nm. The concentration of brine is measured by immersing the MFBG in the liquid, and the minimum detectable refractive index variation can reach 7.2×10^-5 at a refractive index value of 1.33.展开更多
The corrosion behaviors of the Ar F excimer laser copper alloy electrodes were studied. The morphology, composition and impurities were characterized by optical microscope, scanning electron microscopy, electron micro...The corrosion behaviors of the Ar F excimer laser copper alloy electrodes were studied. The morphology, composition and impurities were characterized by optical microscope, scanning electron microscopy, electron microprobe and glow discharge mass spectrometer methods. The anode produces the reef, the corrosion pits, the hole layer and the 1–10 μm level flake impurity. The cathode produces the particles, the sputtering pits, the element reduce layer and the 1 μm level particle impurity. Besides the Cu element, other elements in the alloy participate in the corrosion: Al element in the reef is over 1.5 times of the anode, Zn element in the particles is 1.3 times of the cathode, many trace elements congregate on the copper surface several and even hundreds of times. These elements are responsible to a great degree for the impurities and the rapid energy decline of the long-time idled laser.展开更多
After nearly three decades of innovation in excimer laser,today we are presented with a state of the art generation targeting minimally invasive refractive surgery with high speed laser,faster trackers,pupil monitorin...After nearly three decades of innovation in excimer laser,today we are presented with a state of the art generation targeting minimally invasive refractive surgery with high speed laser,faster trackers,pupil monitoring systems and better customization profiles.These systems are capable of delivering better treatments with less induced postoperative high order aberrations.The results reported by many authors had confirmed the superiority in efficiency and safety profiles of this generation compared to previous generations.Still,current technology is facing major challenges in the correction of high hyperopic errors and in presbyopic treatments,with upgrades in ablation centration and thermal control needed,which will ensure better biomechanical results,as a step closer to perfection in refractive surgery.展开更多
The excimer laser has important applications in many fields. Because of its non-uniform intensity distribution there are some limits in applications. This paper introduces rotational lens array to improve intensity di...The excimer laser has important applications in many fields. Because of its non-uniform intensity distribution there are some limits in applications. This paper introduces rotational lens array to improve intensity distributions. The intensity variation is reduced to 1 percent by computer simulation.展开更多
Background:Excimer laser trabeculostomy(ELT)is a microinvasive glaucoma surgery(MIGS)that creates multiple laser channels through the trabecular meshwork using a cold laser system,which minimizes tissue fibrosis and a...Background:Excimer laser trabeculostomy(ELT)is a microinvasive glaucoma surgery(MIGS)that creates multiple laser channels through the trabecular meshwork using a cold laser system,which minimizes tissue fibrosis and aids in bypassing the main area of resistance to aqueous outflow.The purpose of this review is to evaluate the current body of evidence surrounding ELT in terms of efficacy and review the safety profile of the procedure.Main text:Studies screened had to show clear inclusion and exclusion criteria as well as well-defined outcome measures.PubMed,MEDLINE,EMBASE and the Cochrane Controlled Trial Database were searched.Preferred Reporting Items of Systematic Reviews(PRISMA)guidelines were used to assess for study quality and for any bias.Sixty-four articles were initially identified with 18 meeting preliminary screening criteria.Ultimately,8 studies met inclusion criteria and 2 additional non-referenced publications were also included:1 randomized control trial,4 prospective case series and 5 retrospective studies.Overall studies showed moderate intraocular pressure(IOP)lowering of between 20%and 40%from baseline without medication washout and mostly a decrease in glaucoma medications with few complications.Conclusion:Current literature shows a significant IOP-lowering effect of ELT with a favorable safety-profile in standalone cases or combined with cataract surgery.Limitations to these studies are the lack of controls and washout IOP.Overall,ELT is an attractive MIGS option that does not require any residual device remaining in the angle.展开更多
Theoretical simulation and experiments based on a prism beam expander and an echelle grating are con- ducted to study the dependence of linewidth and pulse energy on incidence angle and slit width. With a larger prism...Theoretical simulation and experiments based on a prism beam expander and an echelle grating are con- ducted to study the dependence of linewidth and pulse energy on incidence angle and slit width. With a larger prism incident angle or narrower slit width, the linewidth becomes narrower while the laser pulse energy becomes lower. However, the pulse energy can be improved by optimally designing the prism beam expander. In addition, a subpicometer linewidth ArF laser is obtained with a double-prism beam expander and an echelle grating.展开更多
Six patients with 95% to 100% occluded atheroseleroticlesions underwent percutaneous transluminal excimer lasercoronary angioplasty (PTELCA). Among them, 5 were maleand ! was female; their age ranged from 28 to 66 yea...Six patients with 95% to 100% occluded atheroseleroticlesions underwent percutaneous transluminal excimer lasercoronary angioplasty (PTELCA). Among them, 5 were maleand ! was female; their age ranged from 28 to 66 years. Fourpatients had LAD stenosis and 2 LCX lesions.Acuteangiographic and clinical success was achieved in all patientsbut one, with a success rate Of 83.3%. It was demonstratedthat PTELCA is a safe and effective therapy for selected pa-tients with coronary artery disease.展开更多
文摘Ge self-assembled quantum dots （SAQDs） are grown with a self-assembled UHV/CVD epitaxy system. Then, the as-grown Ge quantum dots are annealed by ArF excimer laser. In the ultra-shot laser pulse duration, -20ns, bulk diffusion is forbidden,and only surface diffusion occurs, resulting in a laser induced quantum dot （LIQD）. The diameter of the LIQD is 20-25nm which is much smaller than the as-grown dot and the LIQD has a higher density of about 6 ×10^10cm^-2. The surface morphology evolution is investigated by AFM.
文摘In this study,a KrF excimer laser was used to modify the biodegradable Mg-1Ca alloy and the time-evolution degradation behavior of the alloy before and after laser treatment was investigated in simulated body fluid(SBF)solution using immersion tests and electrochemical impedance spectroscopy(EIS).A 5μm melted layer with a homogeneous microstructure and an MgO film on the surface were achieved by laser radiation.Corrosion observations(hydrogen evolution,morphology and corrosion products)and EIS results revealed an improvement of corrosion resistance after laser treatment for 48 h.It was found a two-layer structure developed after 2 h immersion on both the untreated and laser-treated alloys,but the sequence of forming the two layers was opposite and greatly influenced by the laser-treated layer.The time-evolution corrosion processes on the untreated and laser-treated alloys were discussed,providing a better understanding of corrosion behavior of biodegradable Mg alloys modified by excimer laser.
基金Supported by Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2022L201)。
文摘AIM:To investigate the size of functional optical zone(FOZ)after small incision lenticule extraction(SMILE)versus femtosecond laser assisted excimer laser keratomileusis(FS-LASIK)for myopia correction and potential associated factors for FOZ.METHODS:A total of 133 patients who received corneal refractive surgery in our hospital between November 2018 and July 2021 were retrospectively enrolled.There were 63 patients(123 eyes)in SMILE group and 70patients(139 eyes)in FS-LASIK group.The size of FOZ was measured using Pentacam 3-dementional anterior segment analyzer before and 3mo after surgery,so as to analyze postoperative achieved functional optical zone(AFOZ)and its contributing parameters.RESULTS:When planned functional optical zone(PFOZ)was 6.5 mm for both groups,AFOZ was 1.45±0.27 and 1.67±0.25 mm smaller than preoperative FOZ in SMILE group and FS-LASIK group 3mo after surgery.AFOZ in SMILE group was significantly larger than that in FS-LASIK group(P<0.001).Variation of FOZ was negatively correlated with preoperative spherical equivalent(SE)and positively correlated with variation of mean keratometry value(△Km),variation of spherical aberration(△SA),and variation of Q-value(△Q,all P<0.001)in both groups.Multiple variable linear regression equations were△FOZ=1.354-0.1×pre-SE+0.336×△Q+1.462×△SA in SMILE group and△FOZ=1.512+0.137×△Q+0.468×△SA in FS-LASIK group.CONCLUSION:AFOZ is significantly smaller than preoperative FOZ in both SMILE and FS-LASIK groups.With the same PFOZ,larger AFOZ is achieved in SMILE group than in FS-LASIK group.
文摘BACKGROUND Percutaneous coronary intervention can be challenging for ostial coronary artery lesions due to calcium burden and elastic fiber content.Excimer laser coronary atherectomy(ELCA)is a less common treatment for severe calcified coronary ostium lesions.CASE SUMMARY An 81-year-old male presented to the Cardiology Department of Qingdao Municipal Hospital with a 1-year history of chest pain.Coronary angiography showed severe calcific stenosis(approximately 90%)in the right coronary artery ostium.The right coronary artery ostium was unable to be advanced using a 2.5 mm×12.0 mm balloon(NC Sprinter,Medtronic,United States)or dilated using a 2.0 mm×12.0 mm balloon(Sprinter,Medtronic,United States).The patient underwent successful ELCA and balloon dilation of the calcified coronary ostium lesion.CONCLUSION ELCA appears to be a safe and effective treatment for the management of severe calcified coronary ostium lesions.
基金Project supported by the National High Technology Development Program of China （Grant No 2002AA303250） and by the National Natural Science Foundation of China （Grant No 60576056）.
文摘Polycrystalline silicon （poly-Si） thin film has been prepared by means of nickel-disilicide （NiSi2） assisted excimer laser crystallization （ELC）. The process to prepare a sample includes two steps. One step consists of the formation of NiSi2 precipitates by heat-treating the dehydrogenated amorphous silicon （a-Si） coated with a thin layer of Ni. And the other step consists of the formation of poly-Si grains by means of ELC. According to the test results of scanning electron microscopy （SEM）, another grain growth model named two-interface grain growth has been proposed to contrast with the conventional Ni-metal-induced lateral crystallization （Ni-MILC） model and the ELC model. That is, an additional grain growth interface other than that in conventional ELC is formed, which consists of NiSi2 precipitates and a-Si. The processes for grain growth according to various excimer laser energy densities delivered to the a-Si film have been discussed. It is discovered that grains with needle shape and most of a uniform orientation are formed which grow up with NiSi2 precipitates as seeds. The reason for the formation of such grains which are different from that of Ni-MILC without migration of Ni atoms is not clear. Our model and analysis point out a method to prepare grains with needle shape and mostly of a uniform orientation. If such grains are utilized to make thin-film transistor, its characteristics may be improved.
基金Project supported by the National Natural Science Foundation of China(Grant No.61904155)the Science and technology Project of Fujian Provincial Department of Education,China(Grant No.JAT200484)+1 种基金the Natural Science Foundation of Fujian Province,China(Grant No.2018J05115)the Scientific Research Projects of Xiamen University of Technology,China(Grant No.YKJCX2020078).
文摘The diffusion and the activation of phosphorus in phosphorus and fluorine co-implanted Ge after being annealed by excimer laser are investigated.The results prove that the fluorine element plays an important role in suppressing phosphorus diffusion and enhancing phosphorus activation.Moreover,the rapid thermal annealing process is utilized to evaluate and verify the role of fluorine element.During the initial annealing of co-implanted Ge,it is easier to form high bonding energy FnVm clusters which can stabilize the excess vacancies,resulting in the reduced vacancy-assisted diffusion of phosphorus.The maximum activation concentration of about 4.4 ×10^(20) cm^(-3) with a reduced diffusion length and dopant loss is achieved in co-implanted Ge that is annealed at a tailored laser fluence of 175 mJ/cm^(2).The combination of excimer laser annealing and co-implantation technique provides a reference and guideline for high level n-type doping in Ge and is beneficial to its applications in the scaled Ge MOSFET technology and other devices.
文摘We report on the impact of direct ultraviolet germicidal irradiation（UVGI）on reflective optics,used in the excimer laser system Allegretto Eye-Q.The aim of our work was to confirm our hypothesis based on long-rate observations of obtained anomalies in post-operative results that are attributed to degradation of reflective optics upon ultraviolet radiation.The presence of direct UVGI coupled with humidity in the operating environment caused merging anomalies and unwanted post-operative correction values.Ultraviolet-A radiation caused a similar effect on the reflective cover of the mirrors.
文摘Surface of Al 2O 3 ceramic was processed by an excimer laser and the characteristics of topography were examined based on the application of the microelectromechanical system(MEMS). It is indicated that the statistic parameters of surface topography processed by the excimer laser have an obvious regularity. The arithmetic-mean value R a and the root-mean square value R q change with the changing of processing parameters in the same step and trend, and there is a quantitative relation between them.A simplified model is proposed for the excimer laser processing surface profile, whose results of the analysis and calculation agree basically with the experimental data. Furthermore,the surfaces processed by excimer laser are greatly flat. Skewness root-mean-square value Z· q changed little with the change of the technological parameters. The above characteristics depend on the processing principle of excimer laser, quite different from the cutting processing.
文摘Changes of surface morphology following XeCI excimer laser irradiation were investigated for three engineering ceramic materials (Al2O3, Al2O3-SiC nanocomposite and Si3N4). Al2O3 and AI2O3-SiC nanocomposite samples exhibit a smooth rapid melt layer on the surface, and the formation of the metastabfe γ-Al2Oa was observed. A silicon-rich layer on the surface was formed after laser irradiation of Si3N4. The toughness K1c of the materials was measured by the indentation fracture method. After laser irradiation, the toughness of Al2O3, Al2O3-SiC nanocomposite and Si3N4 was improved to various degrees: Al2O3-SiC nanocomposite, 60% (max.); AI203, 40% (max.); Si3N4, 12% (max.).
文摘Thin metallic layers (~ 2 μm) of Ni were deposited on polycrystalline Al2O3. ZrO2 and (Ce-TZP)+Al2O3 ceramic substrates. and further irradiated with pulsed excimer (Xeno chloride) laser pulses. The laser energy density was varied from 0.21 to 0.81 J / cm2 to optimize bending strength. For ZrO2 ceramic, it was found that the strength increases from 530 to 753 MPa at 0.51 J / cm2 irradiation. For Al2O3 and (Ce-TZP)+ Al2O3 the fracture strength also increases in varying degree. The causes of strength increment were discussed.
文摘Ablation experiments of A950 Liquid Crystal Polymer (LCP), as a kind of typical matrix of fibre reinforced polymer composites, are carried out in this paper. Data on the ablation of A950 LCP by excimer laser at 248 nm are presented. The experimental results show that the ablation depth is a linear function of the number of pulse at constant laser fluence, The ablation rate varies with the logorithm of the fluence in a linear manner at different fluences. A satisfactory linear relationship is found between ablation energy and incident fluence. Perhaps due to the plume absorption and thermal effect, the ablation rate varies complicatedly with pulse repetition frequency.
基金supported by the National Natural Science Foundation of China(Grant Nos.62450006,62304217,62274157,62127807,62234011,62034008,62074142,62074140)Tianshan Innovation Team Program(Grant No.2022TSYCTD0005)+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0880000)Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant Nos.2023124,Y2023032)。
文摘The 193 nm deep-ultraviolet(DUV)laser plays a critical role in advanced semiconductor chip manufacturing[1,2],micro-nano material characterization[3,4]and biomedical analysis[5,6],due to its high spatial resolution and short wavelength.Efficient and compact 193 nm DUV laser source thus becomes a hot research area.Currently,193 nm Ar F excimer gas laser is widely employed in DUV lithography systems and serves as the enabling technology for 7 and 5 nm semiconductor fabrication.
文摘Background Children with anisometropic amblyopia are often noncompliant with traditional treatment including spectacules and contact lenses. This study was to evaluate the long-term efficacy of excimer laser in situ keratomileusis （LASIK） for children with high anisometropic amblyopia. Methods A retrospective analysis of 24 children with high unilateral anisometropic amblyopia, who underwent LASIK during the period between August 2000 and September 2005 in our hospital, was conducted. The mean age of these children was （7.4±1.9） years （range 5-14 years） and the mean follow-up period was （33.3±14.2） months （range 18.5-74.2 months）. After LASIK, visual acuity, refraction and far or near stereoacuity were analyzed. Near stereoacuity was measured by the random-dot butterfly stereogram and the pre-school random-dot stereogram, while far stereoacuity was measured by the synoptophore with Yan＇s random-dot stereogram. Results Mean preoperative uncorrected visual acuity was 0.06±0.05, while mean postoperative uncorrected visual acuity was elevated to 0.43±0.33. Mean preoperative best-corrected visual acuity was 0.26±0.22, while mean postoperative best-corrected visual acuity was elevated to 0.67±0.40. For patients with myopic anisometropia, preoperative mean spherical equivalent refraction was （-8.01±2.70） D while postoperative value significantly reduced to （-1.32±2.47） D. For patients with hyperopic anisometropia, preoperative mean spherical equivalent refraction was （ 7.35±1.55） D while postoperative value significantly reduced to （3.30±0.86） D. These results demonstrated that there was statistical difference in these parameters between preoperative and postoperative tests. At the last follow-up, 20 patients had near stereoacuity, and the mean near stereoacuities measured by the random-dot butterfly stereogram and the preschool random-dot stereogram were （149.00±152.93）＂ and （201.05±235.94）＂, respectively. In contrast, 11 patients had far stereoacuity, and the mean far stereoacuity measured by the synoptophore was （210.91±217.51）. Three cases of patients developed mild corneal complications. Conclusion LASIK for the correction of high anisometropia in children with monocular amblyopia may be safe and effective, and this can help effectively conduct postoperative amblyopia training and improve the cure rate.
文摘A method to fabricate fiber Bragg grating （FBG） in an optical microfiber （OM） from a conventional photosensitive fiber is proposed in this letter. The cladding of a conventional photosensitive fiber is etched to 17 pro. The etched fiber is drawn to an OM 6μm in diameter. The photosensitivity of the fabricated OM is effectively reserved. A FBG in the OM （MFBG） is successfully fabricated using a KrF excimer laser at a fluence of 400 mJ/cm2 through a phase mask with a pitch of 1 089.3 nm. The reflectivity of the FBG is approximately 10%, and the 3-dB spectrum bandwidth is 0.13 nm. The concentration of brine is measured by immersing the MFBG in the liquid, and the minimum detectable refractive index variation can reach 7.2×10^-5 at a refractive index value of 1.33.
基金supported by the National Natural Science Foundation of China under Grant No. 61705235
文摘The corrosion behaviors of the Ar F excimer laser copper alloy electrodes were studied. The morphology, composition and impurities were characterized by optical microscope, scanning electron microscopy, electron microprobe and glow discharge mass spectrometer methods. The anode produces the reef, the corrosion pits, the hole layer and the 1–10 μm level flake impurity. The cathode produces the particles, the sputtering pits, the element reduce layer and the 1 μm level particle impurity. Besides the Cu element, other elements in the alloy participate in the corrosion: Al element in the reef is over 1.5 times of the anode, Zn element in the particles is 1.3 times of the cathode, many trace elements congregate on the copper surface several and even hundreds of times. These elements are responsible to a great degree for the impurities and the rapid energy decline of the long-time idled laser.
基金This study has been supported in part by a grant from the Spanish Ministry of Health,InstitutoCarlos III,Red Temática de Investigación Cooperativa en Salud“Patología ocular del envejecimiento,calidad visual y calidad de vida”,Subproyecto de Calidad Visual(RD07/0062)a grant from the Spanish Ministry of Economy and Competitiveness,Instituto Carlos III,Red Temática de Investigación Cooperativa en Salud(RETICS)“Prevención,detección precoz y tratamiento de la patología ocular prevalente,degenerativa y crónica”.Subprograma“dioptrio ocular y patologías frecuentes”(RD12/0034/0007).
文摘After nearly three decades of innovation in excimer laser,today we are presented with a state of the art generation targeting minimally invasive refractive surgery with high speed laser,faster trackers,pupil monitoring systems and better customization profiles.These systems are capable of delivering better treatments with less induced postoperative high order aberrations.The results reported by many authors had confirmed the superiority in efficiency and safety profiles of this generation compared to previous generations.Still,current technology is facing major challenges in the correction of high hyperopic errors and in presbyopic treatments,with upgrades in ablation centration and thermal control needed,which will ensure better biomechanical results,as a step closer to perfection in refractive surgery.
文摘The excimer laser has important applications in many fields. Because of its non-uniform intensity distribution there are some limits in applications. This paper introduces rotational lens array to improve intensity distributions. The intensity variation is reduced to 1 percent by computer simulation.
文摘Background:Excimer laser trabeculostomy(ELT)is a microinvasive glaucoma surgery(MIGS)that creates multiple laser channels through the trabecular meshwork using a cold laser system,which minimizes tissue fibrosis and aids in bypassing the main area of resistance to aqueous outflow.The purpose of this review is to evaluate the current body of evidence surrounding ELT in terms of efficacy and review the safety profile of the procedure.Main text:Studies screened had to show clear inclusion and exclusion criteria as well as well-defined outcome measures.PubMed,MEDLINE,EMBASE and the Cochrane Controlled Trial Database were searched.Preferred Reporting Items of Systematic Reviews(PRISMA)guidelines were used to assess for study quality and for any bias.Sixty-four articles were initially identified with 18 meeting preliminary screening criteria.Ultimately,8 studies met inclusion criteria and 2 additional non-referenced publications were also included:1 randomized control trial,4 prospective case series and 5 retrospective studies.Overall studies showed moderate intraocular pressure(IOP)lowering of between 20%and 40%from baseline without medication washout and mostly a decrease in glaucoma medications with few complications.Conclusion:Current literature shows a significant IOP-lowering effect of ELT with a favorable safety-profile in standalone cases or combined with cataract surgery.Limitations to these studies are the lack of controls and washout IOP.Overall,ELT is an attractive MIGS option that does not require any residual device remaining in the angle.
基金supported by the National Science and Technology Major Project and the Natural Science Foundation of Shanghai,China(No.11ZR1441400)
文摘Theoretical simulation and experiments based on a prism beam expander and an echelle grating are con- ducted to study the dependence of linewidth and pulse energy on incidence angle and slit width. With a larger prism incident angle or narrower slit width, the linewidth becomes narrower while the laser pulse energy becomes lower. However, the pulse energy can be improved by optimally designing the prism beam expander. In addition, a subpicometer linewidth ArF laser is obtained with a double-prism beam expander and an echelle grating.
文摘Six patients with 95% to 100% occluded atheroseleroticlesions underwent percutaneous transluminal excimer lasercoronary angioplasty (PTELCA). Among them, 5 were maleand ! was female; their age ranged from 28 to 66 years. Fourpatients had LAD stenosis and 2 LCX lesions.Acuteangiographic and clinical success was achieved in all patientsbut one, with a success rate Of 83.3%. It was demonstratedthat PTELCA is a safe and effective therapy for selected pa-tients with coronary artery disease.
